Fluid-tight watch case



May 17, 1960 R. MONNIER ETAL 2,936,573

FLUID-TIGHT WATCH CASE Filed Aug. 2, 1956 D41 lbw+ 0 rs ,Q y 4,4 MMV/V/ER fhmgd kyfiw? 2..

United States Patent FLUID-TIGHT WATCH CASE Raymond Monnier and Arnold Kyburz, Neuchatel, Switzerland, assignors to Kyburz & Cie, Neuchatel, Switzerland, a firm of Switzerland Application August 2, 1956, Serial No. 601,766

Claims priority, application Switzerland January 6, 1956 2 Claims. (Cl. 58-90) Our invention has for its object a fluid-tight watch case the bottom of which is fitted through an annular notch inside the case band. According to our invention, said case band is provided along its lower edge with a downwardly opening annular groove the cross-section of the bottom of which is recessed in the shape of a downwardly flaring V while the bottom of the case is provided beyond the notch with an annular projection engaging the above mentioned groove in the case band and the cross-section of which matches the shape of the bottom of said groove.

We have illustrated by way of example in the accompanying drawing a preferred embodiment of a watch case according to our invention. In said drawing:

Fig. 1 is a radial cross-section thereof;

Figs. 2 and 3 illustrate its operation.

The case illustrated includes a case band 1 rigid with a rim 1; on said case band are fitted a glass 2 and a bottom 3 which latter engages the case hand through a peripheral notch 4. The case band is provided along its lower edge with an annular groove 5 the cross-section of the bottom of which is recessed in the shape of a V, the sides of which flare widely apart in a downward direction. On the other hand, the bottom 3 of the case includes on the outside of the notch 4 an annular projection 6 rising slightly above the general plane of said bottom and the upper section of which engages the bottom of the groove 5, the cross-section of said annular projection matching that of said groove. A packing 7 is fitted inside said groove and when the bottom 3 is not fitted over the case band, said packing assumes the shape illustrated in Fig. 2. As soon as the bottom has been fitted over the case band, even to a slight extent, the projection 6 on the bottom 3 engages the packing 7 and urges it upwardly in the direction of the arrow f1 so as to deform it as illustrated in Fig. 3; it exerts thus a pressure on said packing in the direction of the diverging arrows f2 to press it against the bottom and the side walls of the groove whereby an excellent fluid-tightness is obtained.

What we claim is:

1. In a fluid-tight watch-case, the combination of a case band provided along its lower edge with a downwardly opening annular groove, the bottom of which is recessed in the shape of an obtuse, widely open V and the side walls of which start from the edges of the downwardly flaring bottom along surfaces coaxial with the axis of the case band, a case bottom fitted inside the lower edge of the case band inwardly of said annular groove, an annular flange rigid with the outer periphery of the case bottom and including an annular upwardly directed projection the upper surface of which has a radial cross-section matching that of the bottom of the groove and an annular packing fitted between the lastmentioned projection and the bottom of the groove and adapted to fill elastically the entirety of said groove and to engage the sidewalls thereof upon engagement of the case bottom over the case band and consequent engagement of the upper surface of the projection over the lower edges of the groove.

2. In a fluidtight watch-case, the combination of a case band provided along its lower edge with a downwardly opening annular groove, the bottom of which is recessed in the shape of an obtuse, widely open V and the side walls of which start from the edges of the downwardly flaring bottom along surfaces coaxial with the axis of the case band, a case bottom fitted inside the lower edge of the case band inwardly of said annular groove, an annular flange rigid with the outer periphery of the case bottom and including an annular upwardly directed projection the upper surface of which has a radial crosssection matching that of the bottom of the groove and a flat annular packing having a rectangular cross-section when unstressed fitted between the last-mentioned projection and the bottom of the groove and adapted to fill elastically the entirety of said groove and to engage the sidewalls thereof upon engagement of the case bottom over the case band and consequent engagement of the upper surface of the projection over the lower edges of the groove.

References Cited in the file of this patent UNITED STATES PATENTS 572,818 Palmer Dec. 8, 1896 1,268,821 Depollier June 11, 1918 2,116,421 Williams May 3, 1938 2,716,328 Dinstman Aug. 30, 1955 FOREIGN PATENTS 221,353 Switzerland Aug. 17, 1942 287,619 Switzerland Apr. 1, 1953 

